Without limiting the scope of the present disclosure, its background will be described in relation to forming a window in a casing string for a multilateral well, as an example.
In multilateral wells, it is common practice to drill a branch or lateral wellbore extending outwardly from an intersection with a main or parent wellbore. Typically, once the parent wellbore casing string is installed and the parent wellbore has been completed, a whipstock is positioned in the parent wellbore casing string at the desired intersection and then a rotating mill is deflected laterally off the whipstock to form a window through the parent wellbore casing sidewall.
Once the casing window is created, the lateral wellbore can drilled. In certain lateral wellbores, when the drilling operation has been completed, a lateral wellbore casing string is installed in the lateral branch. Casing the lateral branch may be accomplished with the installation of a liner string that is supported in the parent wellbore and extends a desired distance into the lateral wellbore. Once the lateral wellbore casing string is installed and the lateral wellbore has been completed, it may be desirable to reestablish access to the main wellbore. In such cases, a rotating mill may be use to form an access window through the lateral wellbore casing sidewall.
In certain multilateral installations, it may be desirable to drill the lateral wellbore in a predetermined direction from the parent wellbore such as out of the high side of the parent wellbore. In such installations, it is necessary to form the window at a predetermined circumferential orientation relative to the parent wellbore casing. In order to properly position and rotationally orient the whipstock such that the window is milled in the desired direction, a latch assembly associated with the whipstock may be anchored into and rotationally oriented within a latch coupling interconnected in the parent wellbore casing string. The latch assembly typically includes a plurality of spring operated latch keys, each having an anchoring and orienting profile that is received in a latch profile formed internally within the latch coupling. In this manner, when the latch keys of the latch assembly are operatively engaged with the latch profile of the latch coupling, the latch assembly and the equipment associate therewith are axially anchored and circumferentially oriented in the desired direction within the parent wellbore casing string. Importantly, to obtain the proper orientation of the latch assembly, the latch coupling of the parent wellbore casing string must first be positioned in the desired orientation. One way to orient the latch coupling is to rotate the parent wellbore casing string with a drill string using measurement while drilling data. It has been found, however, that rotationally orienting the parent wellbore casing string in this manner can be imprecise and time consuming. Accordingly, a need has arisen for improved systems and methods for orienting a parent wellbore casing string in a wellbore.